The organ, as the instrument appropriate to the church, invariably accompanies the singing, so that in all Mozart's church compositions the bass part is carefully figured, sometimes by his father's hand; it is sometimes, but rarely, employed obbligato, as in the Benedictus (259 K.), and then treated in easy style. Next to the organ come three trombones, essentially the support of the chorus, played in virtue of his office by the "stadtthürmermeister" and two of his subordinates. [53] Following ancient tradition they sounded in the tutti in unison with the three lower voices of the chorus; the trombones were generally left unindicated in the score, and only the places marked where they were to be silent. This curious prominence of the brass instruments, whereby the soprano part is left unrepresented, was usual at that time, and could not be dispensed with in the church. Trombones are seldom used independently by Mozart, and then in the simplest manner. The stringed instruments served as independent orchestra, and were generally only two violins and violoncello; the {ORCHESTRA.} (283) tenors strengthened the violoncello, which went with the organ bass. The stringed instruments were strengthened as far as possible and treated so as to counteract the disadvantage they were at in contrast with the chorus, trombones and organ. When the violins are not with the voices, the passages are disposed so as to have the best effect, and they frequently play in unison; this explains the partiality for running passages for the violins, which are not expressive in themselves, but serve to amplify the rest. It was a higher task to give the violins a character really independent of the chorus--to make them carry out their own motif either in one part only, in opposition to the chorus, or in joint development. In almost all Mozart's masses the effort is visible, at any rate in some places, to treat the stringed instruments independently; as his artistic sense matured, they were used more freely, and with more careful reference to sound effects. As a variation in later works, the damper was sometimes employed, and more rarely, the _pizzicato_. Besides stringed instruments, trumpets and drums were generally used, being almost indispensable for solemn high mass. The constant use of trumpets, as of trombones (sackbuts), was founded on the Bible, which speaks of their employment in the Jewish temple worship; and also careful and highly elaborated trumpet music played so considerable a part in court festivities, that it could not well be dispensed with in church ceremonials. In two masses (139, 167, K.), Mozart has employed, in addition to the two usual trumpets called "clarini," a tromba, which has only to sound the low notes C and G, and to strengthen the drums.[54] As regards other wind instruments, we know that in 1757, "Oboes and German flutes were seldom heard in the cathedral, and the French horn, never."[55]